A photodiode is a light detecting semiconductor device which converts light into an electrical current. A photodiode generally comprises a pn junction or a PIN structure comprising an undoped intrinsic semiconductor region interposed between a p-type semiconductor region and an n-type semiconductor region. Current is generated by photon illumination when photons having at least the bandgap energy of the semiconductor are absorbed in the photodiode. When a photon of such sufficient energy strikes the photodiode, valence band electrons are excited to the conduction band leaving holes in their place in the valence band, thus creating an electron-hole pair.
To detect the angle and direction of an incident light beam of interest, a guiding lens together with several separate photodiodes are generally used. A conventional photodiode has a planar receiving surface, sometimes with an anti-reflective (AR) coating thereon. One known arrangement has a plurality of photodiode chips with each photodiode chip positioned for detecting a different photon angular range. In this arrangement, each individual photodiode needs to be aligned accurately to one another for detected angle accuracy.